[libvirt-users] event handler

[Alexandr]

Michal Privoznik писал 2013-10-14 11:39:
> On 14.10.2013 10:33, Alexandr wrote:
>> Michal Privoznik писал 2013-10-14 08:48:
>>> On 14.10.2013 02:42, Alexandr wrote:
>>>> good day to all.
>>>> i still have not solved my problem with event handling.
>>>> currently i have following code
>>>> 
>>>> 
>>>> void libvirt_eventloop_thr_func()
>>>> {
>>>>     while(true) //TODO: stop somehow on exit
>>>>     {
>>>>         if(virEventRunDefaultImpl() < 0)
>>>>         {
>>>>             virErrorPtr err = virGetLastError();
>>>>             fprintf(stderr, "Failed to run event loop: %s\n", err &&
>>>> err->message ? err->message : "Unknown error");
>>>>         }
>>>>     }
>>>> }
>>>> 
>>>> 
>>>> 
>>>> ...
>>>> 
>>>>     virSetErrorFunc(NULL, libvirt_error_handler);
>>>>     libvirt_connection = virConnectOpen("qemu:///system");
>>> 
>>> Move this line ^^^ ...
>>> 
>>>>     if (virEventRegisterDefaultImpl() < 0)
>>>>     {
>>>>         virErrorPtr err = virGetLastError();
>>>>         fprintf(stderr, "Failed to register event implementation: 
>>>> %s\n",
>>>> err && err->message ? err->message: "Unknown error");
>>>>             return -1;
>>>>     }
>>>>     {
>>>>         int callback =
>>>> virConnectDomainEventRegisterAny(libvirt_connection, NULL,
>>>> VIR_DOMAIN_EVENT_ID_LIFECYCLE,
>>>> VIR_DOMAIN_EVENT_CALLBACK(domain_event_handler), NULL, NULL);
>>>>         if(callback == -1)
>>>>         {
>>>>             std::cout<<"Error: failed to register domain event 
>>>> handle
>>>> callback\n";
>>>>             return -1;
>>>>         }
>>>>     }
>>>> 
>>>>     boost::thread(boost::bind(&libvirt_eventloop_thr_func));
>>> 
>>> ... over here. The virConnectOpen detects if there's an even loop
>>> registered. And in your case you don't have any registered when
>>> calling it.
>>> 
>>> Michal
>> 
>> thank you very match, it now working as expected, but one thing are
>> missed from documentations, current api docs says what i do not need 
>> to
>> call virInitialize(), but if i call virEventRegisterDefaultImpl()
>> without calling virInitialize() programm crashing (i have not used
>> virInitialize() in my programm, just virConnectOpen() as docs said).
>> problem solved now.
> 
> From virInitialize documentation [1]:
> 
> "The only time it would be necessary to call virInitialize is if the
> application did not invoke virConnectOpen as its first API call."
> 
> Which is your case. But if you believe this can be written better,
> propose a patch and I'll review it.
> 
> Michal
> 
> 1: http://libvirt.org/html/libvirt-libvirt.html#virInitialize

yes, i read this, but my first api call is virSetErrorFunc(), and this 
api call working fine without virInitialize(), this create a little 
confusion.

i think i can't help with documentation, english is not my native 
language and it is hard to me to write on it, and mostly impossible to 
write correctly.